1. Field of the Invention
This invention pertains generally to sights such as might be used, for exemplary purposes only, in combination with various projectiles and firing devices. In a more specific manifestation, the invention pertains to mounts used on telescopic sights commonly used for very long distance sighting in association with a rifle or the like.
2. Description of the Related Art
Many years have passed since the first rifles were designed. The original rifles had very little precision, and were equally limited in distance a bullet would travel. With these rifles, the barrel served as an adequate aligning tool. Gradually, new designs permitted riflemen to fire accurately at greater distances, which then led to a need for better ways to align the rifle with an intended target. Early techniques included the use of two small protrusions that extended vertically above the rifle barrel but which formed a common axis with the barrel. These sights were replaced by v-sights still in use today on some modern short-range rifles, where the sight closest to the rifleman""s eye is formed in the shape of the letter xe2x80x9cvxe2x80x9d, and the forward sight may be an edge or protrusion with a small ball on the top thereof. In practice, the shooter will align the ball or top of the protrusion centered and at the top of the xe2x80x9cvxe2x80x9d. This type of sighting technique is reasonably accurate to only tens of yards, and then loses too much accuracy to be of any use. Other early sights included the leaf sight, and peep sights where the xe2x80x9cVxe2x80x9d or xe2x80x9cUxe2x80x9d is replaced by a closed cylinder, forming a small alignment hole. Commonplace with peep sights are hooded front sights, where a small cover is placed over the front sight to reduce the distortion effect of uneven lighting, such as sunlight from one direction or the other, that might otherwise lead to optical misalignment.
As distances increased through improved firing techniques, better bullets and improved barrels, better sights also had to be designed. The telescopic sight, which is essentially a low magnification sighting telescope mounted adjacent the rifle barrel and on an axis roughly parallel thereto, has now become the predominant sight for longer distance shooting. Several benefits are attained, the first which is the additional magnification of the target, which at modem firing distances can be very helpful. A second feature of the telescopic sight in common use today is the elevation and windage adjustment for an internal cross-hair, which permits a shooter to compensate for bullet drop that will occur over distance, in accordance with the laws of physics and gravity, and windage, which is a horizontal or side-to-side adjustment that is made to compensate for drift brought on by a cross-wind. This combination of magnification, internal cross-hairs, and compensation for windage and bullet drop has served the needs of the industry for many years.
Greater shooting distances continue to be sought after, and the physical limitations of the telescopic sight prevent this type of sight from fulfilling desired objectives without some further modification or compensation. Several factors must be taken into consideration for a long distance sight. The first is the desired magnification and field of view. In order to increase field of view at a given magnification, it is customary to enlarge optical components. Unfortunately, the size of the sight is limited by physical relation to the rifle, greater manufactured cost of larger components, and also by the weight that larger optical components and all associated necessary structure add: Said another way, a very large telescope is by definition very bulky, very heavy, very expensive, and requires very special mounting hardware to keep the optics in proper alignment after exposure to firing recoil.
In order to minimize the expense of the telescopic sight, while still permitting compensation for greater distances than would be attainable with the sight components alone, several artisans have proposed adjustable mounting structures for telescopic sights. These adjustable mounts permit the sight to be used at firing distances greater than can be compensated for with the ordinary bullet drop and windage adjustments available on a traditional sight. Exemplary among these patents are U.S. Pat. No. 1,083,288 to Lowe and U.S. Pat. No. 4,397,107 to Holden, each which are incorporated herein by reference in their entirety for their teachings of sights and mountings and the other more general knowledge of the field presented therein. The Holden patent illustrates an approach wherein a top adjustable setting screw is calibrated to permit bullet drop adjustment with relative precision. An adjustable screw member is designed to protrude within a scope mount and extend downward an adjustable distance. Counteracting this downward force is a spring loaded member that extends from the bottom and side up to the scope tube, while two additional side screws are provided for anchoring the scope horizontally within a split mounting ring. Unfortunately, with the Holden design, the scope housing is supported only by each of the four adjustable screws, which leads to a concentration of force and stress upon very small areas of the telescopic sight tube. Given the substantial recoil that may be endured, especially when firing with long-range bullets, the possibility for damaging the scope either during adjustment or during firing is too great. Furthermore, even small flexures within the scope tube housing will lead to inaccurate distance settings by the rifleman, since the adjustment screw will travel into and flex the scope housing without actually changing the angular orientation of the scope. Finally, in the event of recoil, the telescope tube may move and cause both impact damage and frictional wear to the tube, since the tube is reliant upon support from a spring loaded pin. This design is therefore very restrictive in terms of what size and weight of telescopic sight may be permitted for a given firing load and intended shooting distance.
The Lowe patent, which is interestingly of much earlier origin, offers several features that alleviate some of the limitations of Holden. For example, in the Lowe patent, split rings are used to directly clamp about the sighting tube. A secondary framework is provided within which the clamping ring travels. Final position is selected by adjustment with a special thumb wheel and beveled surface, and then the position is locked into place with either a side-mounted screw or a screw and nut combination coming from below the split ring. Unfortunately, using this technique the side mounted screw will tend to pull the sight out of linear alignment with the gun barrel, essentially creating the need for an otherwise unnecessary windage adjustment. Since the Lowe patent provided no convenient way to make such an adjustment, this Lowe design was probably deemed unworkable at the time by other artisans.
Since the time of Lowe, there have been numerous additional U.S. patents promulgated that provide two axis adjustment of a sight. These include U.S. Pat. No. 843,183 to Smith; U.S. Pat. No. 1,361,063 to Joeck; U.S. Pat. No. 2,101,037 to O""Neil; U.S. Pat. No. 2,143,167 to Pechar; U.S. Pat. No. 2,165,796 to Humeston; U.S. Pat. No. 2,208,913 to Unertl; U.S. Pat. No. 2,336,107 to Litschert; U.S. Pat. No. 2,491,431 to Unertl et al; U.S. Pat. No. 3,040,433 to Heinzel; U.S. Pat. No. 3,374,544 to Pitchford; and U.S. Pat. No. 3,826,012 to Pachmayr; each which are incorporated herein by reference for their teachings relevant to the art and to the present specification. In spite of the long need and extensive development, there is still a need in this industry for a precision mount that will accommodate existing telescopic sights and extend the useful range thereof.
Exemplary embodiments of the present invention solve inadequacies of the prior art by providing a precision mount having two split rings that directly engage a telescopic sight. The front split ring is mounted on shoulder bolts to provide a pivoting engagement, while the rear split ring is held within a slide and adjusted vertically therein. A balanced lock is provided which ensures alignment is preserved during position locking. Windage is provided on a separate adjustment between the sight yolk and the rifle attachment, thereby isolating windage from position locking and simplifying the appropriate adjustments.
In a first manifestation, the invention is an adjustable mount for attaching a longitudinally extending sight to a gun barrel. A first pivotal mount affixes the sight at a first location permits rotation relative to the mount. A second adjustable mount generally encompasses and retains the longitudinally extending sight distal to the first location. The second adjustable mount generally encompasses the sight to distribute forces transmitted from gun barrel to sight about a circumference of the sight. A yoke adjacent the second adjustable mount restrains the second adjustable mount against motion perpendicular to an arcuate path extending radially the first pivotal mount and thereby maintains general longitudinal orientation of the longitudinally extending sight. A guide is cooperative with the yoke and second adjustable mount to restrain motion of the second adjustable mount with respect to the yoke to follow the arcuate path radially about said first pivotal mount. A locking fastener has means cooperative with yoke, adjustable mount and guide which operatively locks the second adjustable mount into place relative to the yoke in one of a plurality of angular orientations with respect to the first pivotal mount, and provides balanced forces about the second adjustable mount to maintain longitudinal orientation of the sight during locking.
In a second manifestation, the invention is a rifle mount for supporting a telescopic sight upon a barrel having compensation adjustments of vertical angle for bullet drop and horizontal angle for windage that exceed any adjustments available within the telescopic sight. A forward support for the telescopic sight is pivotal about a first horizontal axis and Secured against motion about a vertical axis. A rearward support for the telescopic sight is pivotal about the first horizontal axis and is secured against motion about a vertical axis. A means is provided for accurately measuring an angle of orientation between telescopic sight and rifle barrel. A means is provided that is cooperative with the rearward support for locking the rearward support against motion about the first horizontal axis. A means for supporting the rearward support relative to rifle barrel is pivotal about a vertical axis, and a means is provided for locating the rearward support at a second angle of orientation measured upon a vertical axis between telescopic sight and rifle barrel.
In a third manifestation, the invention is a gun mount for mounting a telescopic sight to a gun. The mount has a forward yoke, and a means for pivotal attachment between forward yoke and telescopic sight that is rotatable about an axis compensating for bullet drop. A rearward yoke is rigidly aligned with the forward yoke, and a means is provided for supporting the telescopic sight within the rearward yoke and locking the sight relative thereto. A base has means to anchor rigidly to the gun, and a means is provided to pivot the yokes about the base about an axis compensating for windage.
A first object of the invention is to provide a precision telescopic sight mount that will accommodate existing telescopic sights and extend the useful range thereof. A second object of the invention is to isolate windage from elevation position locking. Another object of the present invention is to provide durable means for supporting the telescopic sight that avoids any damage or loss of precision that might otherwise result. A further object of the invention is to ensure precision using existing manufacturing techniques. Yet another object of the present invention is to fulfill the foregoing objectives using available components, where suitable, to benefit from existing volume manufacture and parts availability.